In the past there have been DropBox issues specifically with Auria and they were pretty widespread so we saw a lot of the same problems come in at the same time. Right now everything (seemingly) is working well between Auria Pro and DropBox. I have run tests uploading and downloading all sorts of different files and sizes and haven't received a single error.

If you haven't done so already, try this:

-Open the DropBox app and log out of your account.
-Delete the DropBox app from your iPad
-Redownload DropBox from the Apple App Store
-Open Auria, goto Menu> Settings> tap on the DropBox logo in the lower right
-Log into DropBox when prompted
-Try uploading a file again